Evaluation and analysis of LTPP pavement layer thickness data
-
2002-07-30
Details:
-
Creators:
-
Corporate Contributors:
-
Subject/TRT Terms:
-
Publication/ Report Number:
-
Resource Type:
-
OCLC Number:62189912
-
Edition:Final report
-
Contracting Officer:
-
Corporate Publisher:
-
NTL Classification:NTL-HIGHWAY/ROAD TRANSPORTATION-HIGHWAY/ROAD TRANSPORTATION;NTL-HIGHWAY/ROAD TRANSPORTATION-Materials;NTL-HIGHWAY/ROAD TRANSPORTATION-Pavement Management and Performance;
-
Abstract:In 2001, the Federal Highway Administration sponsored a study to review pavement layer thickness data for Long Term Pavement Performance (LTPP) sites. The main objective of the study was to assess the quality and completeness of pavement layering information and layer thickness data and to provide recommendations for improvement. In the course of the study, layer thickness data available in the LTPP database were examined for quality and completeness using Levels A to E data. Following the data completeness evaluation, pavement layering data were evaluated to determine the consistency of material type and thickness data between different data sources. In addition, layer thickness variability indicators, within-section material type consistency, and material type and thickness reasonableness were evaluated. In the cases where there were inconsistencies in the data, the data were reviewed and reported to the LTPP data managers along with recommendations for data anomaly resolution. In addition, the layer thickness data from Specific Pavement Studies (SPS) experiments were analyzed to determine characteristics of within-section layer thickness variation. The analysis included layers with different material and functional types. Descriptive statistics such as mean, standard deviation, skewness, and kurtosis were computed for each section. The statistical analysis results for 1,034 SPS layers indicated that 84 percent of all layers thickness variations within LTPP section follow a normal distribution. The extent of differences between as-designed (inventory) and as-constructed (measured) layer thickness data was also investigated for the SPS sections. The results of analysis indicate that about 60 percent of all section/layers have mean thicknesses within 6.35 mm (0.25 in) of the target thickness. For a tolerance level of 25.4 mm (1 in), this percentage is above 90 for most layer types and target thickness values. For the same layer and material type, the mean constructed layer thicknesses tend to be above the designed value for the thinner layers and below the designed value for the thicker layers. One important product from this study is the Researcher’s Guide to LTPP Layer Thickness Data. The main purpose of this guide is to provide guidance for the selection of layer material type and thickness data from the LTPP database. The guide also contains a discussion about within-section layer thickness variability and comparison between as-designed and as-constructed layer thickness. The guide is available as a separate publication.
-
Format:
-
Funding:
-
Collection(s):
-
Main Document Checksum:
-
Download URL:
-
File Type: